Citizen Monitoring Program

2015 WATER QUALITY REPORTS AND SUMMARIES
September 3 - 24

Here is the eighth set of UD Citizen Monitoring Reports for 2015 covering the period of September 3rd to 24th. This will be our last report for the season, but we’ll continue to monitor at a reduced frequency in the off-season. Temperatures were within a normal range. Most of the area had 2 or more inches of rain between the 10th and the 12th, but otherwise, conditions remain usually dry.

  • Low Dissolved oxygen (< 4.0 ppm) levels remain widespread, although there have been recent signs of improvement at many sites that are not evident in the report which only lists DO levels below 5 ppm. Severely low readings (< 2.0 ppm) were intermittent in several dead-end canals and 2 upper tributaries (Old Mill and Dirickson creeks).
  • Accumulations of Nuisance Aquatic Vegetation were minor with the exception of Diamond and Wagamons Ponds in Milton, although they appear to on the decline.
  • Total Enterococcus bacteria levels were generally reduced, but remained elevated in 2 upper tributaries (Guinea and Dirickson creeks), and 2 dead-end canals (South Bethany).
  • Harmful algae blooms of potentially toxic Blue Green algae remained widespread in the Broadkill watershed (Red Mill, Diamond and Wagamons ponds, and the Broadkill River tidal pond in Milton) but at generally reduced cell densities. This was the worst year I can remember in 10 years of monitoring the Broadkill. A photo of Microcystisseen from a dock is attached. In the estuaries, 2 dense blooms of a potentially toxic flagellate (Chloromorum) were seen at the Prime Hook NWR boat ramp and at Torquay canal. In the ocean and at the Indian River Inlet, background levels of Dinophysis and Karenia papilionacae continued to be seen.
Aug 21 - Sept 3

Here is the seventh set of UD Citizen Monitoring Reports for 2015 covering the period of Aug 21 to Sept 3. Temperatures were generally within a normal range. If you got any rain, you were lucky. It’s been more than 3 weeks since we’ve seen significant rainfall.

  • Low Dissolved oxygen (< 4.0 ppm) levels remain widespread. Severely low readings (< 2.0 ppm) were limited to several dead-end canals and 2 upper tributaries (Old Mill and Dirickson creeks).
  • Accumulations of Nuisance Aquatic Vegetation were minor with the exception of Diamond and Wagamons Ponds in Milton.
  • Total Enterococcus bacteria levels were elevated in a few tributaries (Guinea creek, Iron branch, Old Mill creek), and a dead-end canal (South Bethany).
  • Harmful algae blooms of some potentially toxic Blue Green algae became more widespread in the Broadkill watershed (Red Mill, Diamond and Wagamons ponds, the Broadkill River tidal pond in Milton, and at the Prime Hook NWR boat ramp). Although the risk of toxicity is probably low, a typical “canary in the coal mine” in our region can be dogs that ingest water or lick algae scum off of their fur. Better to keep the pooch out of noticeably green and opaque water. In the estuaries, only one dense bloom of a potentially toxic flagellate (Heterosigma) was seen in Old Mill creek, mixed in with low levels of Blue-Greens. In the ocean and at the Indian River Inlet, background levels of Karenia papilionacae and Dinophysis persist.
Aug 5 - Aug 20

Here is the sixth set of UD Citizen Monitoring Reports for 2015 covering the period of Aug 5 to Aug 20. Temperatures were generally a bit below normal. Rainfall was greater than normal during the first week, but the second week was dry.

 

  • Low Dissolved oxygen (< 4.0 ppm) levels remain widespread, but severely low readings (< 2.0 ppm) were limited to 2 dead-end canals and the Salt Pond.
  • Accumulations of Nuisance Aquatic Vegetation were minor with the exception of Diamond Pond where extensive floating mats of algae have recently reformed.
  • Total Enterococcus bacteria levels were elevated in some tributaries (Guinea creek and Iron branch), canals (South Bethany and Fenwick) and a bay site (Fenwick). It is likely that rainfall contributed to elevated values, particularly on the 11th (heavy rain on the 7th and 11th).
  • Harmful algae blooms of some potentially toxic Blue Green algae were more widespread, particularly in the Broadkill watershed (Red Mill pond, Diamond pond, and 2 sites in the Prime Hook NWR). In the estuaries, blooms of 2 potentially toxic flagellates were seen in a few canals (Chloromorum and Heterosigma). A notable bloom of 2 non-toxic diatoms was seen in upper Love Creek. In the ocean and at the Indian River Inlet, background levels of Karenia papilionacae and Dinophysis persist.
July 23 - Aug 6

Here is the fifth set of UD Citizen Monitoring Reports for 2015 covering the period of July 23 to Aug 6. Temperatures and rainfall were near normal, but thunderstorms caused rainfall to be highly variable in timing and amounts that fell across different areas.

 

  • Low Dissolved oxygen (< 4.0 ppm) levels remain widespread, and severely low readings (< 2.0 ppm) were seen in several canals and a few tributaries. Typically, DO levels reach seasonal lows in late July and early August.
  • Accumulations of Nuisance Aquatic Vegetation were minor, with the exception of Wagamons Pond. Apparently, algae harvesting by DNREC has been ongoing there recently.
  • Total Enterococcus bacteria levels were elevated in a few tributaries (Iron Branch, Guinea Creek, Burton Prong, Love Creek) and reduced in others (Dirickson and Vines Creeks). Slightly elevated values were seen in a few sites that are usually quite low (Warwick Cove and Cape Shores pier). Both elevated and reduced values could be related recent rainfall, depending on the timing.
  • Harmful algae blooms of potentially toxic species were rather limited. Red Mill pond had a mixture of Blue-Green algae, but at reduced levels relative to the previous sample. The Prime Hook boat ramp had significant levels of Anabaena, a Blue-Green algae common in fresh water, mixed with blooms of several estuarine species. In the estuaries, modest blooms of 3 potentially toxic flagellates were seen in canals (Heterosigma and Fibrocapsa) and one tributary (Chloromorum). In the ocean and at the Indian River Inlet, background levels of Karenia papilionacae and 2 species of Dinophysis persist.
July 2 - 23

Here is the fourth set of UD Citizen Monitoring Program Reports covering the period of July 2 to 23, 2015. Temperatures and rainfall were generally were close to average but rather variable, especially for rain. Some areas received above average rain from heavy thunderstorms.

  • Low Dissolved Oxygen readings (D.O. < 4 ppm) were widespread. At several locations, this condition was consistent. Severely low readings (< 2 ppm) were intermittent in several canals and consistent in one upper tributary of the Broadkill River (Old Mill Creek).
  • Accumulations of Nuisance Aquatic Vegetation were generally minor, but a major accumulation of filamentous algae was present at Diamond Pond (in Milton) early in the period.
  • Total Enterococcus bacteria levels were especially variable relative to the seasonal geometric mean across different site types (canals, tributaries and bay). Notable elevated values were seen in upper Guinea creek and at Fenwick Island bayside.
  • A few different types of notable harmful algae blooms were seen. For fresh water sites, Red Mill Pond had a mixture of potentially toxic and non-toxic blue green algae at moderately high cell densities. For the estuaries, Holly Terrace Acres canal had a mixture of potentially toxic and non-toxic estuarine flagellates and dinoflagellates. Other blooms of non-toxic flagellates or dinoflagellates that could contribute to low DO levels occurred at the Prime Hook boat ramp, the Iron Branch and upper Guinea creek. For the ocean beaches and the Indian River Inlet, background levels a few potentially toxic algae that could impact shellfish resources were seen, but inconsistently. These included Karenia papilionacea, Pseudo-nitzchia and 2 species ofDinophysis.
June 17 - July 1

This is the third set of UD Citizen Monitoring Program Reports for 2015 covering the period of June 17 to July 1. Temperatures were about average, but rainfall was well above average.

  • Low Dissolved Oxygen readings (D.O. < 4 ppm) were fairly widespread, but seemed to rebound above 5 ppm in some areas after heavy rains. Note that the report only lists observations of DO < 5ppm. Severely low readings (< 2 ppm) were seen during both weeks at the Salt Pond, and during the second week at one site in South Bethany. Severely low readings were seen each week in Dirickson Creek at the Road 381 bridge at a depth of 1 m, but surface readings were above 5 ppm.
  • Accumulations of Nuisance Aquatic Vegetation were generally minor. Major accumulations were seen at Diamond Pond and the Salt Pond, but diminished by the end of the period by flushing or decay.
  • Total Enterococcus bacteria levels were elevated in several locations including upper Dirickson Creek, upper Guinea Creek, and the Iron Branch presumably due to recent heavy rain events.
  • Harmful Algae Blooms included a bloom of a non-toxic green Gymnodinium in the ocean off of Key Box Road with background levels at many locations within the estuaries near the Inlets. Blooms of this dinoflagellate have been seen every few years along the coast, but its identity remains uncertain. In the estuaries, blooms of potentially toxic species were limited to Chattonella subsalsa and Chloromorum toxicum in a few canal systems. Low levels of potentially toxic Blue-green algae were seen in some ponds and upper tidal tributaries of the Broadkill River.
May 28 - June 17

This is the second set of UD Citizen Monitoring Program Reports covering the period of May 28 to June 17, so 3 weeks. Temperatures were near average. Most areas received 2-3 inches of rain during the first week of June and scattered storms afterwards. This largely made up for a dry spell in May.

 

  • The incidence of Low Dissolved Oxygen readings (D.O. < 4 ppm) and severely low readings (< 2 ppm) was about the same as in late May. Severely low readings were found 2 canal systems. Curiously, in the second week of June, DO readings rebounded in many locations to the point they do not appear in the report as it only lists readings below 5 ppm.
  • Accumulations of Nuisance Aquatic Vegetation remained minor in most locations. Some the major accumulations in South Bethany have decreased recently whether by natural processes or with help from DNREC’s algae harvester.
  • Total Enterococcus bacteria levels were generally a bit lower than earlier in the season, with the exception of 2 locations, both in shallow somewhat stagnant edge sites that could be influenced by wildlife sources.
  • Harmful Algae Blooms were generally below thresholds of concern. Dinophysis acuminataseemed to leave the estuary but remained at the Indian River and Roosevelt Inlets. Heterosigma akashiwo persisted at fairly high cell densities at the Prime Hook Boat ramp.
April - May

Spring Greetings, Here is the first set of UD Citizen Monitoring Program Reports for 2015 covering April and May. Subsequent reports will be issued every 2 or 3 weeks during summer, and the reports will be archived on this page.

 

  • Spring arrived a bit late this year. Temperatures were below normal in early April, but have been about normal since then. Precipitation was normal in April, but May has been rather dry.
  • As usual, Low Dissolved Oxygen readings (< 4 ppm) began to be detected in upper tributaries and residential canals in May. There was one severely low reading (< 2 ppm) at the Prime Hook boat ramp in late May.
  • Minor accumulations of Nuisance Aquatic Vegetation were widespread, and major accumulations were observed in the South Bethany canals. I also received reports of large mats of floating algae in other locations including Love creek, Arnell creek, White creek and the Salt Pond. Most of this alga appeared to be Enteromorpha sp., a filamentous green alga, and it appears that it is more widespread than usual this year.
  • Total Enterococcus bacteria levels were elevated at many sites in late May but did not appear to be associated with rain events. TE levels were generally lower than normal in late April and early May. Remember that bacteria values can be highly variable, so the geometric mean is a better indicator of general conditions than individual samples.
  • Harmful Algae blooms of a few potentially toxic species most commonly seen in the spring appeared in May. Dinophysis acuminata was consistently seen in Torquay canal and sporadically seen in other locations. Generally, this dinoflagellate is of concern at low cell densities because of the potential for toxin to bioaccumulate in shellfish tissue. Fortunately, it does not appear to produce as much toxin in the mid-Atlantic region as in other locations. Research is ongoing to better understand what the risks are here. Dense, visible, blooms of Prorocentrum minimum andHeterosigma akashiwo were observed in 2 different canals. Both species were also commonly seen at lower cell densities in many locations. Both have been shown to cause detrimental effects to aquatic organisms at high cell densities.

Also, go here to see maps of dissolved oxygen readings taken from shoreline sites for the first 4 weeks of the season.

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